(CNN) - The man who helped uncover Watergate says the Internal Revenue Service controversy doesn't rise to the same level of the Nixon scandal–but could be on its way.
Longtime Washington Post reporter and editor said he suspects the White House had a deeper knowledge of the IRS' targeting of conservative groups than officials are letting on. The public, he added, needs more answers.
"This is not Watergate at all, but the road to Watergate is concealment, is not coming clean and just say 'Oh well we won’t have to release that memo. We won’t have to let so and so testify. Let’s call executive privilege. Let’s stonewall'," he said Monday night. "And if they do that, they will dig themselves in a hole."
President Barack Obama sharply condemned the IRS for mishandling tax-exempt applications from groups with the names "tea party" and "patriot." Last month, he announced that his administration requested and accepted the resignation of then-acting IRS Commissioner Steven Miller over the issue.
White House Press Secretary Jay Carney has repeatedly denied that the White House had a role in the matter, pointing to the audit by the Treasury Department's inspector general for tax administration, which found the problem originated in the Cincinnati IRS office that handles tax-exempt applications.
Carney argues the IRS is an independent agency with only two political appointees, but Woodward said such an argument is "fiction" and "absurd."
"Clearly in the pipeline, lots of people knew some of this or should know it," he said on Fox News’ “The O’Reilly Factor.” "And I agree, this needs to be investigated, but you know who should lead the investigation? President Obama."
A recent Quinnipiac University poll indicates that a plurality of respondents–45%– believe the IRS targeting of conservative groups was a decision made by civil service employees, while 35% believes it came from the Obama administration. Seventy-six percent said a special prosecutor should be appointed to investigate the issue.
But an overwhelming number–73%–said the economy should be a higher priority over investigating the controversies.
A number of conservative and tea party groups will appear Tuesday before a congressional committee to give their side of the story.
Woodward pressed the Washington press corps to keep asking questions about the issue, saying people did not believe at first what he and Carl Bernstein wrote on the Nixon scandal "for a long time."
The Obama administration, he added, isn't "yet in the bunker...the answers are forthcoming" and he believes they have "moral and intellectual capacity" to fill in the holes in the IRS controversy.
"Much hangs in the balance here, not just the reputation of the news media for aggressiveness and some form of neutrality, but the whole relationship that the White House and the government has with the public about trust," he said.